article {
  padding-top: 50px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
}
article .game {
  margin: 10px auto;
  display: grid;
  grid-template-columns: repeat(10, 60px);
  grid-template-rows: repeat(10, 60px);
  position: relative;
}

article .game div {
  cursor: pointer;
  font-size: 40px;
  text-align: center;
  line-height: 60px;
  margin: 1px;
  background-color: chocolate;
  color: beige;
}
.shadow {
  box-shadow: 6px 6px 6px rgb(88, 88, 86), -2px -2px 2px rgb(88, 88, 86);
}
span {
  position: absolute;
  background-color: red;
}
